Modeling and optimization of voltage and treatment time for electrocoagulation removal of hexavalent chromium

The present study was undertaken to optimize process variables, electrolysis voltage and treatment time for the electrocoagulation removal of hexavalent chromium (Cr(VI)). Response surface methodology (RSM) with center composite design was used to achieve energy efficient removal of Cr(VI). Predictive models using ANOVA and multiple response optimization revealed that optimal Cr(VI) removal efficiency occurred at 11 V and 18.6 min treatment time to give 50% Cr(VI) removal efficiency with a consumption of 15.46 KWh m(-3) energy. Multiple response optimization through a desirability function saves 32.3% energy consumption. The models explained 97.5% variability for Cr(VI) reduction efficiency and 99% variability for energy consumption. Artificial neural network (ANN) model was generated to validate the RSM predictions. Validation experiments were performed at proposed optimal conditions proved RSM and ANN predictions. (C) 2010 Elsevier B.V. All rights reserved.